CAJ | 학술논문

目的探讨320排容积CT(320-DVCT)冠状动脉血管成像前瞻性心电门控最佳重建时相,初步评价其对图像质量、曝光剂量及诊断准确性的影响.方法对77例行DVCT心功能扫描的患者[平均扫描心率(70±13)次/min( bpm),范围46～ 102 bpm]做回顾性心电门控扫描,分析最佳重建时相与心率的关系.利用不同心率最佳重建时相作为前瞻性心电门控扫描曝光时相,对53例需接受冠状动脉导管造影的患者[平均扫描心率(75±11) bpm,范围57～114 bpm]同时行冠状动脉CT成像,评价曝光时相对图像质量、曝光剂量及诊断准确性的影响.图像质量评分随机区组多样本比较采用Friedman检验,双变量统计行直线回归分析及Spearman相关分析.结果随着心率的增加,收缩期比例逐渐增高(r=0.78,P＜0.01).收缩期与舒张期最佳重建图像质量随着心率的增加明显下降(r分别为0.38、0.82,P均＜0.01).根据回归方程分析,最佳重建时相按心率分组如下:心率＜ 70 bpm,65％～80％;70～80 bpm,70％～85％;81 ～90 bpm,70％～90％;＞90 bpm,35％～ 50％.利用上述最佳重建时相行前瞻性心电门控扫描结果表明,前瞻性心电门控扫描较回顾性心电门控扫描明显降低辐射剂量[分别为(6.1±3.8)和(12.4±7.0) mSv,t=6.5,P＜0.01],对诊断准确性并无明显影响.但是随着心率的增加,前瞻性心电门控扫描辐射剂量仍会明显增加(r=0.64,P＜0.01).结论DVCT可在更宽心率范围内应用前瞻性心电门控扫描技术对冠状动脉进行准确诊断；但在高心率条件下需要多个心动周期扫描,辐射剂量明显增加,建议尽可能降低患者心率以降低辐射剂量.
목적 탐토320배용적CT(320-DVCT)관상동맥혈관성상전첨성심전문공최가중건시상,초보평개기대도상질량、폭광제량급진단준학성적영향.방법 대77례행DVCT심공능소묘적환자[평균소묘심솔(70±13)차/min( bpm),범위46～ 102 bpm]주회고성심전문공소묘,분석최가중건시상여심솔적관계.이용불동심솔최가중건시상작위전첨성심전문공소묘폭광시상,대53례수접수관상동맥도관조영적환자[평균소묘심솔(75±11) bpm,범위57～114 bpm]동시행관상동맥CT성상,평개폭광시상대도상질량、폭광제량급진단준학성적영향.도상질량평분수궤구조다양본비교채용Friedman검험,쌍변량통계행직선회귀분석급Spearman상관분석.결과 수착심솔적증가,수축기비례축점증고(r=0.78,P＜0.01).수축기여서장기최가중건도상질량수착심솔적증가명현하강(r분별위0.38、0.82,P균＜0.01).근거회귀방정분석,최가중건시상안심솔분조여하:심솔＜ 70 bpm,65％～80％;70～80 bpm,70％～85％;81 ～90 bpm,70％～90％;＞90 bpm,35％～ 50％.이용상술최가중건시상행전첨성심전문공소묘결과표명,전첨성심전문공소묘교회고성심전문공소묘명현강저복사제량[분별위(6.1±3.8)화(12.4±7.0) mSv,t=6.5,P＜0.01],대진단준학성병무명현영향.단시수착심솔적증가,전첨성심전문공소묘복사제량잉회명현증가(r=0.64,P＜0.01).결론DVCT가재경관심솔범위내응용전첨성심전문공소묘기술대관상동맥진행준학진단；단재고심솔조건하수요다개심동주기소묘,복사제량명현증가,건의진가능강저환자심솔이강저복사제량.
Objective To investigate the optimal reconstruction windows for coronary angiography using 320-detector row dynamic volume CT (DVCT) and evaluate their effects on image quality,radiation dose and diagnostic accuracy.Methods From 77 patients [mean heart rate (70 + 13) bpm,range:46-102 bmp] were scanned with retrospective ECG-gating 320-detector row DVCT.The relationship between heart rate and optimal reconstruction windows was analyzed.From 53 patients [mean heart rate ( 75 ±11 ) bpm,range:57-114 bpm] were scanned with prospective ECG-gating 320-detector row DVCT.The effects of prospective ECG-gating on image quality,radiation dose and diagnostic accuracy were evaluated.Friedman test was performed for image quality scores in random groups.Linear regression and Spearman correlation were performed to test bivariate data.Results The proportion of systolic duration in the cardiac cycle increased significantly with higher heart rate (r =0.78,P ＜0.01 ).The image quality in systolic and diastolic phases were significantly influenced by heart rate ( r =0.38,0.82 ; P ＜ 0.01 ).According to the regression analysis of image quality score in different heart rate groups,the optimal reconstruction windows were determined as followed:when heart rate was ＜ 70 bpm,the optimal reconstruction windows should be preset at 65％-80％ ; 70 to 80 bpm,70％-85％ ; 81 to 90 bpm,70％-90％ ; ＞90 bpm,35％-50％.Compared with retrospective ECG-gating,prospective ECG-gating which preset reconstruction windows according to the phases mentioned above,could decrease radiation dose [(6.1 ± 3.8 )vs (12.4 ± 7.0) mSv],without deteriorating the image quality (t =6.5,P ＜ 0.01 ).However,in higher heart rate,the radiation dose of prospective ECG-gating DVCT was still higher ( r =0.64,P ＜ 0.01 ).Conclusions DVCT can provide high image quality in a wide range of heart rate with prospective ECG gating.It is still recommended to control heart rate strictly since the radiation dose increases significantly in high heart rate.